Anti-biofouling of Submerged Lighting Fixtures

ABSTRACT

A retrofit device and method adapt an existing, conventional lighting fixture for resisting bio-fouling of a primary window of the lighting fixture when submerged and exposed to biological organisms within a surrounding environment. The primary window is isolated from the surrounding environment by an auxiliary window member, and ultraviolet radiation is directed to the outer surface of the auxiliary window member from a source within the retrofit device, enabling transmission of ultraviolet radiation to the outer surface of the auxiliary window member of an intensity limited to essentially that which is effective in rendering the outer surface of the auxiliary window member immune to permanent adherence of biological organisms to which that outer surface is exposed when submerged, thereby allowing illumination from a source behind the primary window to be projected effectively through the auxiliary window member into the surrounding environment.

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/537,739, filed Aug. 16, 2019, which is acontinuation-in-part of U.S. patent application Ser. No. 14/957,812,filed Dec. 3, 2015, the entire disclosures of which are incorporatedherein by reference thereto, which applications claim the benefit ofU.S. Provisional Patent Application Ser. No. 62/089,315, filed Dec. 9,2014, the subject matter of which is incorporated herein by referencethereto.

The present invention relates generally to lighting fixtures constructedfor installation where the lighting fixtures will be submerged andthereby exposed to biological organisms that can become attached in suchmanner as to interfere with the transmission of visible light from thelighting fixtures, and pertains, more specifically, to retrofits forproviding anti-biofouling constructions and methods for maintaining suchsubmerged lighting fixtures substantially free of such attachment ofundesirable biological organisms.

With the advent of more effective, more efficient lighting apparatus,there has arisen a greater demand for lighting fixtures that can servein submerged installations where these fixtures will be exposed tobiological organisms that can become attached in a manner that willdefeat the ability to serve the purpose of the installation. Thus, forexample, lighting fixtures installed in marine environments, such as forthe illumination of piers, pilings, seawalls and the like, as well asproviding lighting for a variety of marine vessels, for illuminationthat is meant to serve either or both functional and decorativepurposes, when placed at locations where the lighting fixtures will besubmerged and thereby exposed to the attachment of biological organisms,such as barnacles, algae and the like, will soon lose effectiveness dueto biofouling which will defeat the ability to transmit the desiredillumination.

It has been suggested that ultraviolet radiation (UV) can be effectivein combating biofouling of optical surfaces of various equipmentimmersed for service in marine environments. The present inventionprovides specific retrofit constructions and methods for renderingcurrent, conventional lighting fixtures practical and effective inserving to illuminate a wide variety of installations where the lightingfixtures already are or will be submerged and thereby exposed to thepresence of biological organisms that can defeat the ability of thelighting fixtures to provide effective illumination for eitherfunctional or decorative purposes. Accordingly, the present inventionattains several objects and advantages, some of which are summarized asfollows: Provides retrofit constructions and methods for effectivelycombating biofouling of lighting fixtures installed or ready to beinstalled to furnish lighting for either or both functional anddecorative lighting purposes in environments where the lighting fixturesare submerged and thus exposed to biological organisms that caninterfere with the proper transmission of light from the lightingfixtures; enables more widespread use of lighting fixtures for bothfunctional and decorative lighting purposes where such lighting fixturesare submerged and exposed to the detrimental adherence of biologicalorganisms and the concomitant impedance of the transmission of usablelight as a result of biofouling; renders more economical the use oflighting fixtures in submerged environments, thereby opening theemployment of submerged lighting fixtures over a wider and more diverserange of uses; simplifies the provision of practical anti-biofoulingmeasures in connection with lighting fixtures utilized in installationswherein the lighting fixtures are submerged and exposed to unwantedbiological organisms; allows increased flexibility in the choice ofdesign and construction of lighting fixtures to be submerged inenvironments where the lighting fixtures are exposed to potentialbiofouling; simplifies the installation of submerged anti-biofoulinglighting fixtures in connection with a wide variety of marinestructures, as well as marine vessels, without disturbing the integrityof such structures and vessels; exhibits a high degree of operatingefficiency and effectiveness for more economical performance over anextended service life.

The above objects and advantages are attained by the present invention,which may be described briefly as a retrofit device for being positionedin juxtaposition with an existing lighting fixture that furnishesillumination through a primary window when placed at a marineinstallation location, the retrofit device being constructed forproviding the lighting fixture with resistance to bio-fouling that canimpede the transmission of visible light furnished by the lightingfixture through the primary window when submerged in a surroundingmarine environment wherein the primary window is exposed to visiblelight-impeding bio-fouling marine biological organisms within thatenvironment, the retrofit device comprising: an auxiliary window memberfor transmitting illumination from the primary window of the lightingfixture into the surrounding marine environment, the auxiliary windowmember having an outer surface through which outer surface illuminationfrom the primary window is to pass upon placement of the retrofit devicein position in juxtaposition with the lighting fixture; and a source ofultraviolet radiation carried within the retrofit device and arranged todirect ultraviolet radiation comprised of UVC radiation for transmissionto the outer surface of the auxiliary window member, such that the UVCradiation at the outer surface of the auxiliary window member is of anintensity limited to essentially that which is effective in renderingthe outer surface of the auxiliary window member immune to adherence ofvisible light-impeding bio-fouling marine biological organisms to whichthe outer surface of the auxiliary window member will be exposed whenjuxtaposed with a lighting fixture submerged within the surroundingmarine environment; the auxiliary window member being constructed of amaterial capable of transmitting the UVC radiation from the source ofultraviolet radiation, through the material of the auxiliary windowmember, to the outer surface of the auxiliary window member such thatwhen the retrofit device is juxtaposed with a lighting fixture submergedwithin the surrounding marine environment, visible light-impedingbio-fouling marine biological organisms will be inhibited from adheringpermanently to the outer surface of the auxiliary window member by UVCradiation emanating from the source of UVC radiation carried within theretrofit device and transmitted through the material of the auxiliarywindow member to the outer surface of the auxiliary window member.

In addition, the present invention provides a method for retrofitting anexisting lighting fixture that furnishes illumination through a primarywindow when placed at a marine installation location, the retrofittingproviding the lighting fixture with resistance to bio-fouling that canimpede the transmission of visible light furnished by the lightingfixture through a primary window when submerged in a surrounding marineenvironment wherein the primary window is exposed to visiblelight-impeding bio-fouling marine biological organisms within thatenvironment, the method comprising: juxtaposing with the existinglighting fixture an auxiliary window member in position for transmittingillumination from the primary window of the lighting fixture into thesurrounding marine environment, the auxiliary window member having anouter surface through which outer surface illumination from the primarywindow is to pass upon placement of the auxiliary window member injuxtaposition with the lighting fixture; arranging a source ofultraviolet radiation to direct ultraviolet radiation comprised of UVCradiation for transmission to the outer surface of the auxiliary windowmember, such that the UVC radiation at the outer surface of theauxiliary window member is of an intensity limited to essentially thatwhich is effective in rendering the outer surface of the auxiliarywindow member immune to adherence of visible light-impeding bio-foulingmarine biological organisms to which the outer surface of the auxiliarywindow member will be exposed when juxtaposed with a lighting fixturesubmerged within the surrounding marine environment; and constructingthe auxiliary window member of a material capable of transmitting theUVC radiation from the source of ultraviolet radiation, through thematerial of the auxiliary window member, to the outer surface of theauxiliary window member such that when the auxiliary window member isjuxtaposed with a lighting fixture submerged within the surroundingmarine environment, visible light-impeding bio-fouling marine biologicalorganisms will be inhibited from adhering to the outer surface of theauxiliary window member by UVC radiation emanating from the source ofUVC radiation and transmitted through the material of the auxiliarywindow member to the outer surface of the auxiliary window member.

The invention will be understood more fully, while still further objectsand advantages will become apparent, in the following detaileddescription of preferred embodiments of the invention illustrated in theaccompanying drawing, in which:

FIG. 1 is a partially diagrammatic, longitudinal cross-sectional view ofa submersible lighting fixture constructed in accordance with thepresent invention;

FIG. 2 is a plan view of a component part of the lighting fixture ofFIG. 1;

FIG. 3 is a partially diagrammatic, longitudinal cross-sectional view ofanother submersible lighting fixture constructed in accordance with thepresent invention;

FIG. 4 is a top plan view of a component part of the lighting fixture ofFIG. 3;

FIG. 5 is a partially diagrammatic, longitudinal cross-sectional view ofstill another submersible lighting fixture constructed in accordancewith the present invention;

FIG. 6 is a top plan view of component parts of the lighting fixture ofFIG. 5;

FIG. 7 is a top plan view of a component part of the lighting fixture ofFIG. 5;

FIG. 8 is a top plan view of yet another submersible lighting fixtureconstructed in accordance with the present invention;

FIG. 9 is a partially diagrammatic cross-sectional view taken along line9-9 of FIG. 8;

FIG. 10 is a partially diagrammatic cross-sectioned pictorial view ofanother submersible lighting fixture constructed in accordance with thepresent invention;

FIG. 11 is a partially diagrammatic cross-sectioned pictorial view ofanother submersible lighting fixture constructed in accordance with thepresent invention;

FIG. 12 is a partially diagrammatic cross-sectioned pictorial view ofanother submersible lighting fixture constructed in accordance with thepresent invention;

FIG. 13 is a partially diagrammatic cross-sectioned pictorial view ofanother submersible lighting fixture constructed in accordance with thepresent invention;

FIG. 14 is a partially diagrammatic cross-sectional view of asubmersible lighting fixture constructed in accordance with the presentinvention and shown installed on a marine vessel;

FIG. 15 is a partially diagrammatic, longitudinal cross-sectional viewof another submersible lighting fixture constructed in accordance withthe present invention;

FIG. 16 is a bottom plan view of a component part of the lightingfixture of FIG. 15;

FIG. 17 is a cross-sectional view taken along line 17-17 of FIG. 16;

FIG. 18 an exploded pictorial view, partially diagrammatic, illustratinganother embodiment of the present invention;

FIG. 19 is an enlarged cross-sectional view taken along line 19-19 ofFIG. 18;

FIG. 20 is a pictorial view of the embodiment illustrated in FIG. 18;

FIG. 21 is a pictorial view showing another embodiment of the invention;

FIG. 22 is a pictorial view showing still another embodiment of theinvention;

FIG. 23 is a pictorial view, partially broken away, of the embodiment ofFIG. 22;

FIG. 24 is a pictorial view showing the embodiment of FIG. 22 installedfor use:

FIG. 25 is a side elevational view of yet another embodiment of theinvention; and

FIG. 26 is an enlarged, cross-sectional view taken along line 26-26 ofFIG. 25.

Referring now to the drawing, and especially to FIGS. 1 and 2 thereof, asubmersible lighting fixture constructed in accordance with the presentinvention is shown, partially diagrammatically, at 20 and is seen toinclude a housing 22 having a base 24 and a flange 26. Base 24 is shownmounted upon an underwater post 30 by means of a threaded connection at32. A window member 40 includes a peripheral rim 42 having a pluralityof holes 44 spaced apart circumferentially around the rim 42, and thewindow member 40 is secured to base 24 by a retaining ring 46 throughwhich a plurality of threaded bolts 48 extend within holes 44 to bethreaded into complementary threaded sockets 50 in flange 26 of housing22. A first seal 52 is interposed between retaining ring 46 and rim 42and a second seal 54 is interposed between rim 42 and flange 26, thefirst and second seals 52 and 54 serving to close and seal a chamber 56within housing 22.

A circuit board 60 is placed within chamber 56, mounted upon base 24,and sealed against the environment outside lighting fixture 20 by virtueof placement within the sealed chamber 56. A source of illumination isprovided by a plurality of light sources shown in the form of lightemitting diodes (LEDs) 62 carried by circuit board 60 and operated byelectronic circuitry 64 powered by an external power supply (not shown).LEDs 62 provide illumination which is directed through window member 40to light the environment outside lighting fixture 20. In the illustratedembodiment, post 30 is mounted upon an underwater structure (not shown)and lighting fixture 20 is submerged, exposing lighting fixture 20, andespecially window member 40, to biological organisms in the water withinwhich lighting fixture 20 is submerged. These biological organisms, suchas barnacles, algae and the like, will tend to adhere to window member40 and obscure visible light being directed to the window member 40 bythe LEDs 62 for transmission through the window member 40. Thisphenomenon is known as “biofouling” and will defeat the ability of asubmerged lighting fixture to furnish the visible light desired at theinstallation.

It has been well established that ultra violet radiation is effective incountering the adherence of biological organisms to surfaces where it isdesired to maintain these surfaces free of such biological organisms. Inparticular, ultra violet radiation identified as “UVC” radiation hasbeen found effective in combating those biological organisms encounteredin aquatic environments, and especially in marine environments.Accordingly, in order to maintain window member 40 immune to andsubstantially clear of any accumulation of biological organisms thatcould impede the transmission of illumination through window member 40,a source of UVC radiation is located within chamber 56, here shown inthe form of a UVC LED 80 placed upon circuit board 60 and located sothat UVC radiation is directed to window member 40. Window member 40 isconstructed of a material, such as quartz, that is capable oftransmitting UVC radiation, so that UVC radiation emanating from LED 80will be transmitted through window member 40 to inhibit adhering ofbiological organisms upon the exterior surface 82 of window member 40and thereby combat biofouling of window member 40. Energy is conservedby limiting the intensity of the transmitted UVC radiation at theexternal surface 82 to essentially that which is effective in renderingthe external surface 82 immune to adherence of biological organisms. Inthe illustrated embodiment, window member 40 advantageously isconstructed with exterior surface 82 having a domed configuration, andLED 80 is placed at a focal point of the domed configuration so that theintensity of UVC radiation is substantially uniform over the exteriorsurface 82. LED 80 is controlled by electronic circuitry 64 and, in thepreferred arrangement, LED 80 need not be activated continuously, and isactivated periodically, in timed, intermittent sessions, so as toconserve energy.

Housing 22 preferably is constructed, or at least coated, with amaterial that will resist biofouling, as well as corrosion, forlong-term service. In addition, sealed chamber 56 preferably isevacuated, or is filled with an inert gas, such as nitrogen, to promotereliability and longevity of LEDs 62 and 80, as well as electroniccircuitry 64.

The embodiment illustrated in FIGS. 3 and 4 is shown in the form of asubmersible lighting fixture 120 and is constructed similar tosubmersible lighting fixture 20 described in connection with FIGS. 1 and2. Accordingly, corresponding component parts are labeled with the samereference characters and operate in the same manner as described abovein connection with lighting fixture 20. However, in lighting fixture120, window member 140 has a flat configuration, with a flat exteriorsurface 182, as opposed to the domed configuration of window member 40,the flat configuration providing both functional and decorativedifferences better suited to particular installations.

Turning now to FIGS. 5 through 7, another embodiment of the presentinvention is illustrated in the form of submersible lighting fixture 220and is seen to have a housing 222 with a base 224, a flange 226 and arecess 228. Base 224 is shown mounted upon an underwater post 230 bymeans of a threaded connection at 232. A window member 240 includes aperipheral section 242, and is secured to base 224 by a retaining frame246 juxtaposed with peripheral section 242 through which frame 246 aplurality of threaded bolts 248 extend within holes 244 to be threadedinto complementary threaded sockets 250 in flange 226 of base 224. Afirst seal 252 is interposed between retaining frame 246 and peripheralsection 242, and a second seal 254 is interposed between peripheralsection 242 and base 224, the seals 252 and 254 serving to close andseal a chamber 256 within housing 222.

A circuit board 260 is placed within chamber 256, mounted upon base 224,and sealed against the environment outside lighting fixture 220 byvirtue of placement within the sealed chamber 256. A plurality of lightemitting diodes (LEDs) 262 are carried by circuit board 260 and areoperated by electronic circuitry 264 powered by an external power supply(not shown). LEDs 262 provide illumination which is directed throughwindow member 240 to light the environment outside lighting fixture 220.

Window member 240 has a predetermined thickness T, and a perimetric edge270 that follows a largely rectangular path. A flat portion 272 islocated along the perimetric edge 270 of window member 240, the flatportion 272 being adjacent flange 226 and spaced laterally a shortdistance from flange 226 to provide clearance for a source of UVCradiation, shown in the form of a UVC LED 280 coupled with window member240 at the flat portion 272 along the perimetric edge 270 of windowmember 240. A lead 282 connects LED 280 to electronic circuitry 264 foroperating LED 280. In the preferred construction, semi-rectangularportion 284 of perimetric edge 270 is coated with a UVC reflectivematerial 286 such that upon activation of LED 280, UVC radiation isdirected into window member 240 and, by virtue of internal reflection,normally is not dissipated out of window member 240 until such time as abiological organism comes into sufficient attachment to the outersurface 290 of window member 240, at which time UVC radiation within thewindow member 240 will be transmitted, by virtue of such attachment, tothe interfering biological organism, resulting in the offendingbiological organism being neutralized so as to maintain the outersurface 290 sufficiently clear. In this manner, window member 240functions similar to a waveguide, assisted by thickness T, providing UVCradiation only where, when and in an intensity limited essentially tothat needed to maintain the outer surface 290 sufficiently clear ofbiofouling, thereby conserving energy.

With reference to FIGS. 8 and 9, another submersible lighting fixtureconstructed in accordance with the present invention is shown, partiallydiagrammatically, at 320 and is seen to include a housing 322 having abase 324 and a flange 326. Base 324 carries a threaded post 330. Awindow member 340 includes a peripheral rim 342 having a plurality ofholes 344 spaced apart circumferentially around the rim 342, and thewindow member 340 is secured to base 324 by a retaining ring 346 throughwhich a plurality of threaded bolts 348 extend within holes 344 to bethreaded into complementary threaded sockets 350 in flange 326 of base324. A first seal 352 is interposed between retaining ring 346 and rim342 and a second seal 354 is interposed between rim 342 and flange 326,the first and second seals 352 and 354 serving to close and seal achamber 356 within housing 322.

A circuit board 360 is placed within chamber 356, mounted upon base 324,and sealed against the environment outside lighting fixture 320 byvirtue of placement within the sealed chamber 356. A plurality of lightemitting diodes (LEDs) 362 are carried by circuit board 360 and areoperated by electronic circuitry 364 powered by an external power supply(not shown). LEDs 362 provide illumination which is directed throughwindow member 340 to light the environment outside lighting fixture 320.In the illustrated embodiment, lighting fixture 320 is mounted upon anunderwater structure, shown in the form of a hull 370 of a marinevessel, and is submerged, exposing lighting fixture 320, and especiallywindow member 340, to biological organisms in the water within whichlighting fixture 320 is submerged. Lighting fixture 320 is secured inplace by advancing a threaded nut 372 along threaded post 330 untillighting fixture 320 is secured upon hull 370. A sealing member 374 isinterposed between base 324 and hull 370, and a further sealing member376 is interposed between threaded nut 372 and hull 370 to seal the hull370. As described hereinbefore, biological organisms, such as barnacles,algae and the like, will tend to adhere to window member 340 and obscurevisible light being directed to the window member 340 by the LEDs 362for transmission through the window member 340. This phenomenon, knownas “biofouling,” will defeat the ability of a submerged lighting fixtureto furnish the visible light desired at the installation.

Accordingly, in order to maintain window member 340 immune to andsubstantially clear of any accumulation of biological organisms thatcould impede the transmission of illumination through window member 340,a source of UVC radiation is located within chamber 356, here shown inthe form of a UVC LED 380 placed upon circuit board 360 and located sothat UVC radiation is directed to window member 340. Window member 340is constructed of a material, such as quartz, that is capable oftransmitting UVC radiation, so that UVC radiation emanating from LED 380will be transmitted through window member 340 in an intensity limitedessentially to that which is effective to inhibit adhering of biologicalorganisms upon the exterior surface 382 of window member 340 and therebycombat biofouling of window member 340.

The embodiment of the invention illustrated in FIG. 10 is in the form ofa submersible strip lighting fixture 420 having a housing 422 of aselected extended length, with a base 424 and a flange 426. Base 424carries a number of threaded posts 430 along the length of the base 424for mounting lighting fixture 420 upon a length of underwater structure.A window member 440 includes laterally opposite edges 442. The windowmember 440 is secured to base 424 by retaining members 446 through whicha plurality of threaded bolts 448 extend to be threaded into flange 426of base 424. A first seal 452 is interposed between each retainingmember 446 and window member 440, and second seals 454 are interposedbetween window member 440 and base 424. The seals 452 and 454, togetherwith opposite end caps, one of which end caps is shown at 458, serve toclose and seal a chamber 456 within housing 422.

A circuit board 460 is placed within chamber 456, mounted upon base 424,and sealed against the environment outside lighting fixture 420 byvirtue of placement within the sealed chamber 456. A plurality of lightemitting diodes (LEDs) 462 are carried by circuit board 460 and areoperated by electronic circuitry 464 powered by an external power supply(not shown). LEDs 462 provide illumination which is directed throughwindow member 440 to light the environment outside lighting fixture 420.

In order to maintain window member 440 immune to and substantially clearof any accumulation of biological organisms that could impede thetransmission of illumination through window member 440, sources of UVCradiation are located within chamber 456, here shown in the form of LEDs480 placed within corresponding waveguides 482 carried by circuit board460 and located so that UVC radiation of an effective limited intensityis directed to window member 440, distributed throughout the extendedlength of lighting fixture 420. Waveguides 482 and window member 440 areconstructed of a material, such as quartz, that is capable oftransmitting UVC radiation, so that UVC radiation emanating from LEDs480 will be distributed to and pass through window member 440 to inhibitadverse accumulation of biological organisms upon the longitudinallyextended exterior surface 484 of window member 440 and thereby combatbiofouling of window member 440.

In the embodiment shown in FIG. 11, visible light emanates from bothfaces 500 of a submersible lighting fixture constructed in accordancewith the present invention. Here again, a lighting fixture is in theform of strip lighting fixture 520 of selected, extended longitudinallength, having a housing 522 with a base 524. However, here base 524includes opposite flanges 526. A window member 540 extendslongitudinally along each face 500, and each window member 540 includeslaterally opposite edges 542. Each window member 540 is secured to base524 by retaining members 546 through which a plurality of threaded bolts548 extend to be threaded into a corresponding flange 526 of base 524.Seals 552 and 554 are provided, as before, together with opposite endcaps, one of which end caps is shown at 558, to close and seal chambers556 within housing 522.

A plurality of light emitting diodes (LEDs) 562 are placed within eachchamber 556, sealed against the environment outside lighting fixture 520by virtue of placement within a corresponding sealed chamber 556, andare operated by corresponding electronic circuitry powered by anexternal power supply (not shown). LEDs 562 provide illumination whichis directed through window members 540 to light the environment outsidelighting fixture 520.

In order to maintain window members 540 immune to and substantiallyclear of any accumulation of biological organisms that could impede thetransmission of illumination through window members 540, sources of UVCradiation are located within each chamber 556, here shown in the form ofLEDs 580 placed within corresponding waveguides 582 located along theextended length of lighting fixture 520 so that UVC radiation isdirected to window members 540, distributed throughout the extendedlength. Waveguides 582 and window members 540 are constructed of amaterial, such as quartz, that is capable of transmitting UVC radiation,so that UVC radiation emanating from LEDs 580 will be distributed to andpass through window members 540 to inhibit adverse accumulation ofbiological organisms upon the exterior surfaces 584 of window members540 and thereby combat biofouling of window members 540.

Turning now to FIG. 12, another submersible lighting fixture constructedin accordance with the present invention is shown in the form of anelongate lighting fixture 620 of selected, extended longitudinal length,having a housing 622 with a base 624 and a flange 626. A window member640 includes laterally opposite edges 642 and is secured to base 624 byretaining members 646 which, together with end caps (not shown),establish a sealed chamber 656 in a manner similar to that describedabove.

A circuit board 660 is placed within chamber 656, mounted upon a bracket658 affixed to housing 622, and sealed against the environment outsidelighting fixture 620 by virtue of placement within the sealed chamber656. A plurality of light emitting diodes (LEDs) 662 are carried bycircuit board 660 and are operated by electronic circuitry 664 placedwithin sealed chamber 656 and powered by an external power supply (notshown). LEDs 662 provide illumination which is directed through windowmember 640 to light the environment outside lighting fixture 620.

In order to maintain window member 640 immune to and substantially clearof any accumulation of biological organisms that could impede thetransmission of illumination through window member 640, sources of UVCradiation are located within chamber 656, here shown in the form of LEDs680 placed within a waveguide 682 carried by circuit board 660 andlocated so that UVC radiation is directed to window member 640,distributed throughout the extended length of lighting fixture 620.Waveguide 682 and window member 640 are constructed of a material, suchas quartz, that is capable of transmitting UVC radiation, so that UVCradiation emanating from LEDs 680 will be distributed to and passthrough window member 640 to inhibit adverse accumulation of biologicalorganisms upon the exterior surface 684 of window member 640 and therebycombat biofouling of window member 640.

In the embodiment of the invention illustrated in FIG. 13, anothersubmersible lighting fixture constructed in accordance with the presentinvention is shown in the form of an elongate lighting fixture 720 ofselected, extended longitudinal length, having a housing member 722extending longitudinally along the selected length. Housing member 722has a semi-tubular configuration including a C-shaped cross-sectionalcontour. A window member 740 is in the form of a tubular structure 742having a circular cross-sectional configuration essentiallycomplementary to the cross-sectional configuration of housing member 722so that window member 740 is received and retained within housing member722, along the length of lighting fixture 720, while providing a window744. End caps (not shown) are secured to housing member 722 to establisha sealed chamber 756 in a manner similar to that described above.

A circuit board 760 is placed within chamber 756, mounted upon a bracket758 secured within window member 740, and is sealed against theenvironment outside lighting fixture 720 by virtue of placement withinthe sealed chamber 756. A plurality of light emitting diodes (LEDs) 762are carried by circuit board 760, along the extended length of lightingfixture 720, and are operated by electronic circuitry 764 placed withinsealed chamber 756 and powered by an external power supply (not shown).LEDs 762 provide illumination which is directed through window 744 tolight the environment outside lighting fixture 720.

In order to maintain window 744 immune to and substantially clear of anyaccumulation of biological organisms that could impede the transmissionof illumination through window 744, sources of UVC radiation are locatedwithin chamber 756, here shown in the form of LEDs 780 placed within awaveguide 782 carried by circuit board 760 and located along theextended longitudinal length of lighting fixture 720 so that UVCradiation is directed to window 744, distributed along the extendedlongitudinal length. Waveguide 782 and window member 740 are constructedof a material, such as quartz, that is capable of transmitting UVCradiation, so that UVC radiation emanating from LEDs 780 will bedistributed to and pass through window 744 to inhibit adverseaccumulation of biological organisms upon the exterior surface 784 ofwindow 744 and thereby combat biofouling of window 744.

With reference to FIG. 14, another submersible lighting fixtureconstructed in accordance with the present invention is shown, partiallydiagrammatically, at 820 and is seen to include a housing 822 having abase 824 and a flange 826. Lighting fixture 820 is shown mounted uponthe hull 830 of a marine vessel 832 having a wall 834 constructed of amaterial now in common use in marine vessels, namely, a fiberglassreinforced synthetic polymeric material. The construction of lightingfixture 820 enables the lighting fixture 820 to be mounted upon hull 830without compromising the integrity of wall 834. To that end, housing 822is placed against outer face 836 of wall 834, in registration with aninternal housing 838 placed against inner face 840 of wall 834, asshown. Housing 822 carries self-aligning rare earth magnets 842 affixedwithin housing 822 and which align with self-aligning rare earth magnets844 carried by and affixed within internal housing 838. In this manner,corresponding magnets 842 and 844 are attracted to one another to securein place housing 822, without the necessity for creating an unwantedopening or other compromising structural element in wall 834.Preferably, a resilient pad 846 is interposed between housing 822 andwall 834 to inhibit further any tendency toward unwanted movement oflighting fixture 820 along hull 830.

A window member 850 includes a peripheral rim 852 and is secured to base824 by a retaining ring 856 through which a plurality of threaded bolts858 extend to be threaded into flange 826 of base 824. First and secondseals 862 and 864 close and seal a chamber 866 within housing 822.

A plurality of light emitting diodes (LEDs) 872 are placed withinchamber 866, sealed against the environment outside lighting fixture 820by virtue of placement within the sealed chamber 866 and are operated byelectronic circuitry 874 powered by an external power supply 880. Inorder further to assure that wall 834 is maintained uncompromised, powersupply 880 is coupled to a power induction transmitter 882 placed withininternal housing 838, located within hull 830, and a power inductionreceiver 884 is placed within housing 822, in proximity to powerinduction transmitter 882. Power is transmitted to induction receiver884 which is connected to an LED controller 886 which, in turn, isconnected to electronic circuitry 874, all within housing 822. An RFtransmitter/controller 888 within the vessel 832 communicates with LEDcontroller 886 for enabling control of the LEDs 872, through electroniccircuitry 874. In this manner, controlled power is furnished to LEDs 872so as to provide desired illumination directed through window member 850to light the environment outside lighting fixture 820. As describedherein above, biological organisms, such as barnacles, algae and thelike, will tend to adhere to window member 850 and obscure visible lightbeing directed to the window member 850 by the LEDs 872 for transmissionthrough the window member 850. This phenomenon, known as “biofouling,”will defeat the ability of a submerged lighting fixture to furnish thevisible light desired at the installation.

Accordingly, in order to maintain window member 850 immune to andsubstantially clear of any accumulation of biological organisms thatcould impede the transmission of illumination through window member 850,a source of UVC radiation is located within chamber 866, here shown inthe form of a UVC LED 890 placed upon circuit board 870 and located sothat UVC radiation is directed to window member 850. Window member 850is constructed of a material, such as quartz, that is capable oftransmitting UVC radiation, so that UVC radiation emanating from LED 890will be transmitted through window member 850 to inhibit adverseaccumulation of biological organisms upon the exterior surface 892 ofwindow member 850 and thereby combat biofouling of window member 850.

Turning now to FIGS. 15 through 17, another embodiment of the presentinvention is illustrated in the form of submersible lighting fixture 920and is seen to have a housing 922 with a base 924, a flange 926 and arecess 928. A threaded post 930 extends from base 924 for mountinglighting fixture 920 in place at a selected installation site. A windowmember 940 includes a peripheral border 942, and is attached to base 924by being securely fitted within flange 926 of base 924 to close and seala chamber 956 within housing 922.

A circuit board 960 is placed within chamber 956, mounted upon base 924,and sealed against the environment outside lighting fixture 920 byvirtue of placement within the sealed chamber 956. A plurality of lightemitting diodes (LEDs) 962 are carried by circuit board 960 and arepowered by an external power supply (not shown). LEDs 962 provideillumination which is directed through window member 940 to light theenvironment outside lighting fixture 920.

Window member 940 has a predetermined thickness T, and a perimetric edge970 that preferably follows a largely circular path. A cavity 972 islocated within window member 940, the cavity 972 preferably beingadjacent perimetric edge 970 and spaced laterally a short distance fromperimetric edge 970, cavity 972 being dimensioned and configured toaccommodate a source of UVC radiation, shown in the form of a UVC LED980 inserted within window member 940 adjacent the perimetric edge 970of window member 940. LED 980 is coupled with circuit board 960 foroperating LED 980. In the preferred construction, window member 940 isconstructed of a material, such as quartz, that is capable oftransmitting UVC radiation, so that UVC radiation emanating from LED 980will be transmitted through window member 940. Perimetric edge 970 isprovided with a coating 986 of UVC reflective material along theperimetric edge 970 such that upon activation of LED 980, UVC radiationis directed into window member 940 and, by virtue of internalreflection, normally is not dissipated out of window member 940 untilsuch time as a biological organism comes into sufficient attachment tothe outer surface 990 of window member 940, at which time UVC radiationwithin the window member 940 will be transmitted, by virtue of suchattachment, to the interfering biological organism, resulting in theoffending biological organism being neutralized and detached so as tomaintain the outer surface 990 sufficiently clear. In this manner,window member 940 functions similar to a waveguide, assisted bythickness T, providing UVC radiation only where and when needed,essentially in an intensity limited to that which is effective tomaintain the outer surface 990 sufficiently clear of biofouling, therebyconserving energy.

With reference now to FIGS. 18 through 20, there is illustrated aconventional lighting fixture 1000 constructed for use at locationswhere lighting fixture 1000 will be exposed to biological organismswhich cause biofouling that interferes with the transmission of visiblelight furnished by such lighting fixtures. Lighting fixture 1000 is seento include a casing 1100 having a flange 1110 surrounding a primarywindow 1112 through which visible light is projected from inside casing1100 into a surrounding environment. In order to combat biofouling ofprimary window 1112 when lighting fixture 1000 is installed in a marineenvironment, a further embodiment of the present invention is providedin the form of a retrofit device, shown at 1120.

Retrofit device 1120 includes an auxiliary window member in the form ofauxiliary window 1122 secured within a retention band 1124 that extendsaround the perimetric edge 1126 of the auxiliary window 1122. A housing1128 is integrated with retention band 1124 and houses electroniccircuitry 1130 that accepts power from an external power source 1132,through power cable 1134 which directs power to a UVC LED 1140 insertedinto the material of auxiliary window 1122 such that UVC radiation fromUVC LED 1140 is transmitted into auxiliary window 1122 and is presentedto and distributed over surface 1142 of auxiliary window 1122.

In the illustrated preferred embodiment, retrofit device 1120 includesan affixation construct shown in the form of an adhesive 1150 extendingalong retention band 1124, provided either as an adhesive tape or alayer of adhesive applied directly to retention band 1124, in place tojuxtapose auxiliary window 1122 with primary window 1112 by affixingretention band 1124 to flange 1110 of lighting fixture 1000 and to sealprimary window 1112 against exposure to the surrounding environmentwhile, at the same time, securing in place auxiliary window 1122 which,when UVC LED 1140 is activated, presents UVC radiation at outer surface1142 of an intensity limited essentially to that which is effective inrendering the outer surface 1142 of auxiliary window 1122 immune topermanent adherence of visible light impeding biofouling marinebiological organisms to which the outer surface 1142 of the auxiliarywindow 1122 will be exposed when lighting fixture 1000 is submergedwithin the marine environment.

Turning now to FIG. 21, a conventional lighting fixture is shown in theform of lighting fixture 2000 mounted upon a hull, a fragment of whichis illustrated in phantom at 2010, of a marine vessel wherein lightingfixture 2000 will be exposed to surrounding seawater (not shown).Lighting fixture 2000 includes a casing 2012 that extends into theinterior 2014 of the hull 2010 while a flange 2016 of housing 2012 issealed against the exterior 2017 of hull 2010, and presents a lightingfixture primary window 2018. As described above in connection withlighting fixture 1000, a retrofit device 2020 is affixed to flange 2016and provides UVC radiation, from a UVC LED (not shown) placed within ahousing 2022 to an auxiliary window 2024. In a manner described inconnection with retrofit device 1120, auxiliary window 2024 is securedwithin a retention band 2026 and an affixation construct shown in theform of an adhesive 2028 affixes and seals retention band 2026 in placeupon flange 2016 to juxtapose auxiliary window 2024 with primary window2018.

Housing 2022 is extended along hull 2010, at an extension 2030, andpower is transmitted through hull 2010 by induction from a source 2032within the hull 2010. In this manner, the integrity of hull 2010 ismaintained, while installation of retrofit device 2020 is facilitated.

With reference now to FIGS. 22 through 24, a conventional lightingfixture 3000 is adapted for use in a salt water marine environmentwherein surrounding saltwater enables the incorporation into a retrofitdevice, shown at 3010, a self-powered system 3012 for powering theretrofit device 3010. Thus, in the present embodiment, retrofit device3010 is provided with first and second electrodes 3022 and 3024, affixedin place on a retention band 3026 for exposure to salt seawater withinwhich lighting fixture 3000 is to be immersed. First electrode 3022serves as an anode and may be constructed of a suitable material, suchas magnesium, while second electrode 3024 serves as a cathode and may beconstructed of stainless steel, copper or titanium. When affixed andsealed to conventional lighting fixture 3000 at adhesive 3028, as seenin FIG. 24, in a manner similar to that described above, and immersed insalt seawater, which then serves as an electrolyte, electrodes 3022 and3024 generate power that is transmitted to electronic circuitry 3030placed within a housing 3032, as seen in FIGS. 22 and 23, to power a UVCLED 3034 located adjacent perimetric edge 3035 of auxiliary window 3036,coupled to the material of auxiliary window 3036, all within housing3032, as seen in FIGS. 22 and 23, rendering retrofit device 3010self-powered, and simplifying the adapting of conventional lightingfixture 3000 to combat biofouling when submerged in seawater.

Turning now to FIGS. 25 and 26, another retrofit device constructed inaccordance with the present invention is shown at 4000 and is seen toinclude an auxiliary window 4010 constructed of a material, such asquartz, that is capable of transmitting UVC radiation. A slot 4012within auxiliary window 4010 is located in juxtaposition with perimetricedge 4014 of auxiliary window 4010 and receives a UVC LED 4020 carriedby a depending leg 4022 of a circuit board 4024, the depending leg 4022being inserted into slot 4012. Power delivered by a cable 4030 isdirected to circuit board 4024 and powers UVC LED 4020 to generate UVCradiation which is confined to and distributed throughout auxiliarywindow 4010, enhanced by a reflective material in the form of coating4032 that extends along the perimetric edge 4034 of auxiliary window4010. A housing 4040 encloses the circuit board 4024, and an adhesivelayer 4042 is juxtaposed with the perimetric edge 4014 of auxiliarywindow 4010, enabling auxiliary window 4010 to be secured and sealeddirectly to a conventional lighting fixture (not shown) in place tocombat biofouling when that lighting fixture is submerged in a marineenvironment.

It will be seen that the present invention attains all of the objectsand advantages summarized above, namely: Provides retrofit constructionsand methods for effectively combating biofouling of lighting fixturesinstalled or ready to be installed to furnish lighting for either orboth functional and decorative lighting purposes in environments wherethe lighting fixtures are submerged and thus exposed to biologicalorganisms that can interfere with the proper transmission of light fromthe lighting fixtures; enables more widespread use of lighting fixturesfor both functional and decorative lighting purposes where such lightingfixtures are submerged and exposed to the detrimental adherence ofbiological organisms and the concomitant impedance ofthe transmission ofusable light as a result of biofouling; renders more economical the useof lighting fixtures in submerged environments, thereby opening theemployment of submerged lighting fixtures over a wider and more diverserange of uses; simplifies the provision of practical anti-biofoulingmeasures in connection with lighting fixtures utilized in installationswherein the lighting fixtures are submerged and exposed to unwantedbiological organisms; allows increased flexibility in the choice ofdesign and construction of lighting fixtures to be submerged inenvironments where the lighting fixtures are exposed to potentialbiofouling; simplifies the installation of submerged anti-biofoulinglighting fixtures in connection with a wide variety of marinestructures, as well as marine vessels, without disturbing the integrityof such structures and vessels; exhibits a high degree of operatingefficiency and effectiveness for more economical performance over anextended service life.

It is to be understood that the above detailed description of preferredembodiments of the invention is provided by way of example only. Variousdetails of design, construction and procedure may be modified withoutdeparting from the true spirit and scope of the invention, as set forthin the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A retrofit device forbeing positioned in juxtaposition with an existing lighting fixture thatfurnishes illumination through a primary window when placed at a marineinstallation location, the retrofit device being constructed forproviding the lighting fixture with resistance to bio-fouling that canimpede the transmission of visible light furnished by the lightingfixture through the primary window when submerged in a surroundingmarine environment wherein the primary window is exposed to visiblelight-impeding bio-fouling marine biological organisms within thatenvironment, the retrofit device comprising: an auxiliary window memberfor transmitting illumination from the primary window of the lightingfixture into the surrounding marine environment, the auxiliary windowmember having an outer surface through which outer surface illuminationfrom the primary window is to pass upon placement of the retrofit devicein position in juxtaposition with the lighting fixture; and a source ofultraviolet radiation carried within the retrofit device and arranged todirect ultraviolet radiation comprised of UVC radiation for transmissionto the outer surface of the auxiliary window member, such that the UVCradiation at the outer surface of the auxiliary window member is of anintensity limited to essentially that which is effective in renderingthe outer surface of the auxiliary window member immune to adherence ofvisible light-impeding bio-fouling marine biological organisms to whichthe outer surface of the auxiliary window member will be exposed whenjuxtaposed with a lighting fixture submerged within the surroundingmarine environment; the auxiliary window member being constructed of amaterial capable of transmitting the UVC radiation from the source ofultraviolet radiation through the material of the auxiliary windowmember, to the outer surface of the auxiliary window member such thatwhen the retrofit device is juxtaposed with a lighting fixture submergedwithin the surrounding marine environment, visible light-impedingbio-fouling marine biological organisms will be inhibited from adheringpermanently to the outer surface of the auxiliary window member by UVCradiation emanating from the source of UVC radiation carried within theretrofit device and transmitted through the material of the auxiliarywindow member to the outer surface of the auxiliary window member. 2.The retrofit device of claim 1 including a seal for precluding exposureof the primary window to the surrounding environment upon juxtapositionwith the retrofit device to the existing lighting fixture.
 3. Theretrofit device of claim 2 including an affixation construct placed foraffixing the retrofit device with the existing lighting fixture with theauxiliary window member located in juxtaposition with the primary windowsuch that illumination provided by the existing lighting fixture andtransmitted through the primary window is further transmitted throughthe auxiliary window member.
 4. The retrofit device of claim 3 whereinthe affixation construct comprises an adhesive.
 5. The retrofit deviceof claim 1 wherein the auxiliary window member includes a perimetricedge, and the source of ultraviolet radiation is located adjacent theperimetric edge.
 6. The retrofit device of claim 5 wherein the source ofultraviolet radiation is inserted within the material of the auxiliarywindow member.
 7. The retrofit device of claim 1 wherein the auxiliarywindow member includes a perimetric edge, the source of ultravioletradiation is located adjacent the perimetric edge, and a UVC reflectivematerial extends along the perimetric edge.
 8. The retrofit device ofclaim 7 wherein the source of ultraviolet radiation is inserted withinthe material of the auxiliary window member.
 9. The retrofit device ofclaim 7 including an affixation construct placed for affixing theretrofit device juxtaposed with the existing lighting fixture with theauxiliary window member located in juxtaposition with the primary windowsuch that illumination provided by the existing lighting fixture andtransmitted through the primary window is further transmitted throughthe auxiliary window member.
 10. The retrofit device of claim 9 whereinthe affixation construct comprises an adhesive.
 11. The retrofit deviceof claim 10 wherein the auxiliary window member includes a perimetricedge, the source of ultraviolet radiation is located adjacent theperimetric edge, and a UVC reflective material extends along theperimetric edge.
 12. The retrofit device of claim 11 wherein the sourceof ultraviolet radiation is inserted within the material of theauxiliary window member.
 13. The retrofit device of claim 1 including aself-powered system carried by the retrofit device for powering thesource of ultraviolet radiation upon submersion within the surroundingmarine environment.
 14. The retrofit device of claim 13 wherein theself-powered system includes an anode and a cathode, each placed uponthe retrofit device for exposure to the surrounding marine environment,the anode and the cathode each being constructed of a material capableof reacting with the surrounding marine environment to generate power,and electronic circuitry connected to the anode and to the cathode, andto the source of ultraviolet radiation, for directing the power to thesource of ultraviolet radiation.
 15. The retrofit device of claim 14including an affixation construct placed for affixing the retrofitdevice in juxtaposition with the existing lighting fixture with theauxiliary window member located in juxtaposition with the primary windowsuch that illumination provided by the existing lighting fixture andtransmitted through the primary window is further transmitted throughthe auxiliary window member.
 16. The retrofit device of claim 14 whereinthe affixation construct comprises an adhesive.
 17. A method forretrofitting an existing lighting fixture that furnishes illuminationthrough a primary window when placed at a marine installation location,the retrofitting providing the lighting fixture with resistance tobio-fouling that can impede the transmission of visible light furnishedby the lighting fixture through a primary window when submerged in asurrounding marine environment wherein the primary window is exposed tovisible light-impeding bio-fouling marine biological organisms withinthat environment, the method comprising: juxtaposing with the existinglighting fixture an auxiliary window member in position for transmittingillumination from the primary window of the lighting fixture into thesurrounding marine environment, the auxiliary window member having anouter surface through which outer surface illumination from the primarywindow is to pass upon placement of the auxiliary window member injuxtaposition with the lighting fixture; arranging a source ofultraviolet radiation to direct ultraviolet radiation comprised of UVCradiation for transmission to the outer surface of the auxiliary windowmember, such that the UVC radiation at the outer surface of theauxiliary window member is of an intensity limited to essentially thatwhich is effective in rendering the outer surface of the auxiliarywindow member immune to adherence of visible light-impeding bio-foulingmarine biological organisms to which the outer surface of the auxiliarywindow member will be exposed when juxtaposed with a lighting fixturesubmerged within the surrounding marine environment; and constructingthe auxiliary window member of a material capable of transmitting theUVC radiation from the source of ultraviolet radiation, through thematerial of the auxiliary window member, to the outer surface of theauxiliary window member such that when the auxiliary window member isjuxtaposed with a lighting fixture submerged within the surroundingmarine environment, visible light-impeding bio-fouling marine biologicalorganisms will be inhibited from adhering to the outer surface of theauxiliary window member by UVC radiation emanating from the source ofUVC radiation and transmitted through the material of the auxiliarywindow member to the outer surface of the auxiliary window member. 18.The method of claim 17 wherein the step of juxtaposing the auxiliarywindow member with the existing lighting fixture comprises adhering theauxiliary window member in juxtaposition with the existing lightingfixture.
 19. The method of claim 17 including providing a self-poweredsystem carried by the retrofit device for powering the source ofultraviolet radiation upon submersion within the surrounding marineenvironment.
 20. The method of claim 19 including placing an anode and acathode in juxtaposition with the auxiliary window member for exposureto the surrounding marine environment, constructing the anode and thecathode each of a material capable of reacting with the surroundingmarine environment to generate power, and connecting electroniccircuitry to the anode and to the cathode, and to the source ofultraviolet radiation, so as to direct the power to the source ofultraviolet radiation.